Telecommunication cables of the waterproof type are today coming into wide-spread use. As often in the case of non-waterproof cables, atactic polypropylene flooding compound is applied between their protective sheathes about the cable core to inhibit entry of water. With waterproof cables however the cable core itself is also filled with a jelly-like substance such as petroleum jelly or an extended thermoplastic rubber. This latter material, commonly referred to as a filling compound, is usually present in a much larger quantity than the flooding compound. It serves to inhibit migration along the core of any water which has managed to enter the cable core notwithstanding the presence of the flooding compound.
The abundant presence of such sticky, jelly-like filling compound has inhibited reclamation of waterproof cables. Telecommunication cables manufactured without jelly core may be reclaimed through the use of choppers or granulators and air gravity tables. These devices respectively liberate plastic insulation from the metallic conductors of the cable core and separate the cable sheathing and conductors from each other and from the liberated insulation. However, cables manufactured with jelly severely restrict both liberation and separation of the components since the jelly tends to adhere the various constituents together and to the processing equipment. For example, where the material is processed through a series of granulators with progressively smaller size grates, those grates with openings of less than one inch rapidly become fouled with the jelly.
Recently, efforts have been made to devise a system for reclaiming jelly filled telecommunication cables. One such approach has been the addition of a dry agent such as clay to absorb the jelly and form a mass of dry particles that may be reclaimed as before by chopping and air gravity table separation. Unfortunately, this approach has been impractical and cost inefficient due to the need for another material merely to serve as a transport medium in the reclamation process. The presence of clay has also created dust pollution and equipment wear. The use of solvent baths has also been tried but has not proven to be commercially feasible due to solvent loss and redistillation requirements. Steam showering has been tried too but found to be of insufficient effectiveness. The use of pyrolysis and incineration techniques, although possessing technical possibilities, require excessively high capital outlays for commercialization.
Accordingly, there remains a need to provide an effective yet cost efficient process for reclaiming telecommunication cables of the type that includes a jelly-like substance. It is to this task which the present invention is primarily directed.